body{
    background: #000;
}

.code {
    font: 800 2em/1 sans-serif;
    color: hsl(120deg, 100%, 50%);
    writing-mode: vertical-rl;
    white-space: nowrap;
    letter-spacing: 1ch;
    position: absolute;
    text-shadow: -12px 0 8px #0f0;
    animation: rain 3s infinite;
}

.code::after {
    content: '';
    position: absolute;
    z-index: 2;
    inset: 0;
    background: linear-gradient(180deg, rgb(0 0 0 / 100%), transparent);
}

@keyframes rain{
    0%{
        transform: translateY(-100%);
        rotate: y 0deg;
        opacity: 1;
    }
    25%,75%{
        opacity: 0.8;
    }
    35%,65%{
        opacity: 1;
    }
    100%{
        transform: rotate(0deg) translateY(100vh);
        rotate: y 720deg;
        opacity: 1;
    }
}